Apparatus for and method of air conditioning



March 23, 194-3. 5 RUSSEL 2,314,558

' APEARATUS FOR AND METHOD OF AIR CONDiTIONING Filed May 14, 1955 1 sSheets- Sheet 1 Fiel INVENTOR March 23, 1943. P. s. RUSSEL. 2,314,558

APPARATUS FOR AND METHOD OF AIR CONDITIONING Filed May 14, 1935 I5Sheets-Sheet 2 a FIG 2 fix ATT NEY March 23, 1943. s, RUSSEL 2,314,558

APPARATUS FOR AND METHOD OF AIR CONDITIONING l i I I 756/ ATTO EYpointed out, and distinctly claimed;

Patented Mar. 23, 1943 APPARATUS FOR AND DIETHOD OF AIR CONDITIONINGPhilip Sherman Russel, Detroit, Mich, assignor to Detroit LubricatorCompany, Detroit, Mich, a

corporation of Michigan Application May 14, 1935, set-a1 No. 21,353

25Claims.

My invention relates in general to the method of and apparatus forconditioning the air in a room or other enclosed space, and moreparticularly to the'metlgod of and apparatus for controlling therelative humidity of the air in a room or other enclosed space.

One of the'objects of my invention is to provide a new and improvedmethod of and apparatus for maintaining the highest possible relativehumidity of the air in a room or other enclosed space for all outdoortemperatures below a given predetermined degree of temperature withoutresultant precipitation of the moisture of theroom air on a window paneor other heat transmitting room wall surface.

Another object of my invention is to provide a new and improved methodof and apparatus for controlling the heating of a roomor other enclosedspace in a manner so that the supply of heat to the room is expeditedand the time period following the demand for heat by the room thermostator other controlling device is decreased, and to also prevent thetemperature of the room air from being heated to a degree of temperatureexcessively above that for which the thermostat is set.

Another object of the invention is to provide a new and improved methodof and apparatus for maintaining a given predetermined desired humidityin a room for all outdoor temperatures above a predetermined-degree oftemperature to prevent dehumidifying the air of the room to a point inexcess of that necessary forcomfort.

Another object of my invention is to provide a new and improved methodof and apparatus for preventing stagnation of the air in a room or otherenclosed space and resultant cold 'zone at the floor of the room-on theof! phase of the burner..

The invention consists inthe method of control and the device orapparatus for performing the same, to b more fully described hereinafterand the novelty of which will be particularly In the"accompanying-drawings, to be taken as a part of this specificatiom lhave fully and c1early"illustrated an air conditioning system and theapparatus for controlling the same by which my method may be-performed,in which drawings-v Figure l is a diagrammatic view of air conditioningsystem invention; 1

Fig. 2 is a diagrammatic --view of a modified a.

embodying features of my.

form of my air conditioning system embodying other features of myinvention;

Fig. 3 is a detail view showing the manner of arranging temperature andhumidity controldevices of the air conditioning system, with a windowpane of a room; I

Fig. 4 is a plan view of Fig. 3, and

Fig. 5 is an enlarged view or the temperature and humidity controldevice employed in the system of Fig. 2.

Fig. 6 is a view similar to Fig. 3 showing another arrangement of thetemperature and humidity control device relative to a window pane.

When cold outdoor air of any relative humidity is heated to atemperature of 70 F., its relative humidity decreases and it is thecon-' sensus of opinion. that if the air of a room'is heated to atemperature of 70 F., the relative humidity of the room air should, fromthe standpoint of health and comfort, be maintained tive humiditywithout condensation of room air,

moisture on a window pane or other heat transferring room wall surface.when outdoor temperature is below that which will permit the maintenanceof the room air at a relative humidity of without condensation takingplace on a window pane, the nearest approach to the desired 40% relativehumidity of the room air without condensation taking place may beobtained by maintaining a relative humidity of the room air at thewindow pane just under relative humidity. It is likewise advisable thatwhen the outdoor temperature is above a predetermined temperature thatvthe maintenance of the room air atfthe window none at 100% relativehumidity be discontinued. When the outdoor temperature has increasedabove a predetermined temperature, the normal relative humidity of theoutdoor atmosphere will not be detailed dscription necessary, and toa-point where indoor temperatures become uncomfortable, an. improvedcomfort condition mayabe obtained by the dethe drawings for a more of myinvention, and more particularly to Fig. 1, there is shown an airconditionin'gsystem for conditioning the air of a room or other enclosedspace and this system humidifylng ot the room air.

Refening now to electrically operated, the

includes a heating apparatus l, a humidiiying apparatus of which onlythe moisture supply control device 2 is-shown, a motor 3 of adehumidifying apparatus (not shown), and control means designated ingeneral at 4 for controlling the operation of the heating, humidifyingand dehumidifying devices. Preferably the heating apparatus is of theoil burning type having a burner (not shown) preferably driven by anelectric motor 6. The control mechanism 4 comprises in general athermostat 1 and a humidostat including a moisture absorption element 8expansible and contractible in accordance with the moisture content ofthe ambient or surrounding air. The humidostat and thermostat arepreferably mounted on a supporting member, preferably a panel or board9, and the board 9 is preferably secured on or arranged in closeproximity to a window pane I, Fig. 3, or other heat transmitting roomwall surface so that the thermostat is affected by outdoor temperatureand the humidostat element is affected by the moisture content of theroom air cooled by outdoor temperatures.

The thermostat I, in the present system, by reason of its arrangementwith the window pane I is in good heat transfer relation with outdoortemperature. It wil. also be seen that the humidostatexpansible-contractible element 8 is in the path of circulating room airand is responsive to the moisture content of v the room air but atoutdoor temperatures because of its arrangement adjacent the window paneat which point the room air is cooled by and substantially to outdoortemperatures.

Preferably the air conditioning apparatus is humidostat including acontact or switch arm l2 pivotally mounted on the board 9, as at l3, andprovided on its free end and on opposite sides thereof with insulatedcontacts I4 and P5. The 'expansible-contractible element 8 is preferablylocated at one side of the lever arm l2 and with one end abutting thearm l2 preferably near its pivot point l3 so that relatively smallexpansion or contraction of the element 8 will result in the free end ofthe lever being moved through a relatively large are. A spring l8 havingone end fixed to the lever 12 and the other to the board 9 is undertension to maintain the lever l2 in engagement with the end of theexpansible-contractible element 8.

A contact supporting member which may be in the form of a plate I! ispivotally mounted on the supporting board 9 and carried by the plate I!are two spaced contacts l8 and I9, one on each side of the lever arm l2,and arranged to be engaged by thecontacts I4 and I5 respectively of thelever arm i2. Preferably the plate I1 is provided with a handle 20 bymeans of which it may be pivoted and by so doing, position one or theother of the contacts 18 and I9, carried thereby, closer to or fatheraway from its respective contact I4 or l5 of lever l2. In winter, thecontact ll of the lever l2, cooperates with contact l8 to make and breakthe circuit through expansion or contraction of the element 8 while insummer, the contact l5 of lever I2 cooperates with contact l9 to makeand break the circuit. The contacts I8 and [9 are preferablyindividually adjustable relative to their respective contacts I and 15of lever 12 so as to provide for obtaining a second and more accuratespacing between the contacts. To this end contacts l8 and I9 may befixed on the ends of screws 2| threaded in bosses formed on the plate H.The thermostat 1 has a bimetallic element or arm 22 movable in responseto change in outdoor temperature, and on the free end of-a,

the arm 22 and on opposite sides thereof are provided contacts 23 and24. Mounted on the board 9 are spaced contacts 25 and 26, one on eachside of the arm 22 for engagement by the contacts 23 and 24 respectivelyof the arm 22.

As shown in Fig. 4, the supporting board 9 is provided withsubstantiallyparallel side members or flanges 21, and preferably thesupporting board 9 is arranged in relation to the window pane I0 so thatthe longitudinal edges of the side members 21 are against or'in closeproximity to the inner side of the window pane Ill. The window pane I0thus cooperates with the inner walls of panel 9 and its side members 21to define a chamber 28, the top and bottom of which is open for thepassage of air therethrough. The thermostat and humidostat are mountedon the inner wall of panel 9 within the chamber 28. By reason of thewindow pane forming one side of the control device housing, it will beunderstood that the room air in or passing through chamber 28 is cooledby outdoor temperature transmitted to the chamber or space 28 by theheat transmitting window pane l0 and that the temperature within chamber28 is substantially the same as the outdoor temperature and varies inaccordance with change in outdoor temperature, with the result that thethermostat is responsive to changes in outdoor temperature. Likewise thehumidostat element 8 is operable in response to change in the moisturecontent of the room air but at the temperature of the airpassing throughchamber 28. The air flow through chamber 28 is the result of a downdraft of air from the relatively cold I window pane.

In order to support the board 9 in relation to the window pane l0 sothat the thermostat and humidostat willbe in good heat transfer relationwith the outdoor temperature and also so that ready access may be had tothe thermostat and humidostat without necessity of removing screws orother attaching means, I provide a hinge 29 for supporting the board 9and a spring 38 for resiliently maintaining the board 9 against thewindow pane ID, as shown in Fig. 4. The hinge 29 may be of any suitabletype and has one side or leaf fixed to the board 9, and the other sideor leaf fixed to the window frame 29*, such as by screws. The spring 39,which may be a coiled spring, has one end fixed to the pivotal side ofthe hinge with the other end fixed to the other side of the hinge and sopositioned as to exert a force on the pivoted side to urge the sametoward the window pane. When it is desired to adjust the thermostat orhumidostat, it will be seen that ready access may be had thereto byswinging the hinged panel 9 away from the window pane. When the board orpanel 9 is swung away from the window to the point where the spring ismoved over center, it will be seen that the spring then acts to hold theboard 9 away from the window. By providing a hinged board, as abovedescribed, for supporting the thermostat and humidostat relative to awindow pane, it will be appreciated that the window pane can be washedwithout inconvenience since the board canbe swung out .of the way andalso if desired the window can The contact 25.0f the thermostat isconnected by a lead wire 32 to one end of the usual coil 33 of a relayswitch 33. The other end of coil 33* is connected to one side of thesecondary of a transformer 34. The other side of the secondary of thetransformer is connected by a lead wire 35 to the bimetallic element 22and therethrough to contact 23. A lead wire 31 connects the wire 32 tothe contact M of the humidostat lever l2 and a lead wire 33 connects thecontact 26 of the thermostat to the contact I of the humidostat. Thecontrol device 2 of the humdifying or moisture supply apparatus islocated in the moisture supply line or pipe 39 and includes a valve forcontrolling the admittance of moisture to the air of a room. Preferablythe valve is electrically operated such as by a solenoid having theusual movable core 4!] surrounded by a coil 4|. As shown, the valve maybe an integral part of the core, if desired, and in .the presentarrangement is moved to open the valve port when the coil 4| isenergized and moves by gravity to close the valve port when the coil 4|is deenergized. The coil 4| is connected by a lead wire 42 in serieswith contact l8 of the humidostat device and the secondary of thetransformer 34. A manually operated switch 42 may be provided in leadwire 42 between the control valve and the secondary of the trans-'former by means of which the circuit tothe valve may be opened manually.

The dehumidifying device may be of any suitable type, the motor 3preferably being electrically operated. A lead wire 43 connects thehumidostat contact I9 to the controller (not shown) of the motor 3 and alead wire 44 runs from the controller of motor 3 to the secondary of thetransformer 34. The primary of the transformer 34 may be supplied fromthe usual 110 volt line through lead wires 46 .and 47. In a lead wire 50is provided a room thermostat 5| in parallel circuit with the primary ofthe transformer 34 for controlling the operation of the oil burner orother heat supplying apparatus to maintain a predetermined desiredtemperature in a room.

In series with the room thermostat 5| is a safety control device 53,which may be of any well known type, for preventing the temperature ofthe heat conveying medium in the furnace boiler, which may be water orsteam or any other suitable medium, from being heated to an excessivedegree of temperature which might re-- sult in damage to the boiler orto the heating plant in general. The control device 53 may be. mountedon the furnace I, as shown, and may be'of a type which is operable inresponse to changes in temperature of the heat conveying medium in thefurnace boiler, or of a type which is responsive to changes'in pressurewithin the boiler. If a temperature responsive device is employed, itmay be set to operate, when the temperature of the heat conveying mediumin the boiler rises to a predetermined degree of temperature, to openthe circuit to the burner motor 6 to decrease the burner flame. Forconvenience of exposition, the temperature at which the control devicewill operate to open the circuit to the burner motor 6 will behereinafter referred to as 250 F. It will be understood that normallythe room thermostat 5| operates, when the temperature of the room israised to the required degree, to open the circuit to the burner motor6, but .if for some reason the room thermostat should fail to do so thesafety control device would act to open the circuit after thetemperature of the boiler is raised to 250. When the temperature of theboiler decreases below 250, the control device closes the circuit. Theelectric blower motor 6, of the oil burner, is connected to the controldevice 53 by lead wire 54 and is connected to the primary lead wire 41by means of a lead wire 55.

In parallel circuit with the room thermostat 5| and in series circuitwith the safety control device 53 is a second control device 56 fromwhich a lead wire 51 connects the same to the primary wire 46. The relayswitch 33 is provided in lead wire 51, the energizing and. deenergizingof the switch coil 33 being controlled by the thermostat element 1. Thecontrol device 56, which may be termed the minimum control device, maybe of any suitable well known type and like the safety control device53, it may be of a type which is responsive to changes in boilertemperature or one which is responsive to change in pressure in thefurnace boiler. The minimum control device 56 may also be mounted on thefurnace, as shown, and this control device is adapted to close thecircuit at its point of location in the circuit when the temperature orpressure in the boiler is below a minimum established temperature orpressure, and if the relay'switch 33 is closed, the circuit will becompleted to the burner motor 6 Whichwill then be energized to operateand raise the temperature or pressure to the desired point. After thetemperature of the boiler is raised to the predetermined degree forwhichthe control device 56 is set, the control device opens the circuitat its point of location which, however, as will be seen, does not openthe circuit to the motor 6 of the oil burner unless the room thermostatcontact is in open circuit position. The temperature of the boiler belowwhich thecontrol device will close the circuit will be referred tohereinafter as F.

The various lead wires associated with the control means 4 andconnecting the temperature and humidity controls in the electricalcircuit may be neatly arranged, as shown in Fig. 5, and be broughttogether adjacent the lower edge of the board 9 and be enclosed in asheath. or outer covering 28 In order to provide a neat appearing deviceand also one which may be readily moved out of the way when it isdesired to wash or open the window, I provide a plug and socketconnection in the lead wire. The socket, indicated at 3|, may be mountedon the window sill, as shown in Figs. 3 and 6, or it may be mounted inany other suitable place and manner. By removing the plug, indicated at3|, it will be seen that the board 9 and controls carried thereby may beswung away from the window. In

Fig. 6 the control devices, their supporting board devices having anormal position adjacent the window pane and being adapted to be movedaway from the window pane l0 with the'hinged board,- when desired. Theshowing of Fig. 6 differs from that of Fig. 3 in that the controldevices and cooperating supporting structure are mounted on a sidemember of the window sash 3| instead of on the window frame 29, as inFig. 3, so as tobe movable with the window. One leaf or side of thehinge 29 may be attached to the window sash 3| such as by means ofscrews, or in any other suitable manner. Since the control device andsupporting means are carried by the window sash, the window may bereadily raised after removing the plug 3|.

For winter operation, the humidity control device is adjusted so as tomaintain the relative humidity of the room air just under the point atwhich precipitation would take place on a window pane or other heattransmitting room wall surface, or maintaining the dew point temperaturejust under that of the window pane. By arranging the humidostat adjacentthe window pane 9, it will be understood that-theexpansible-contractible element is afiected by the moisture content ofthe room air but at a temperature dependent upon and variable with theoutdoor temperature, or in other words, the expansiblecontractibleelement is affected by the relative humidity of the room air at thewindow pane. Accordingly, if the humidostat is set so as to control theadmittance of moisture to the room air, to maintain a desiredsubstantially constant relative humidity'slightly less than 100% at thewindow pane, the relative humid ty of the room air will be maintained ata point below that at which precipitation would take place on a windowpane. It is generally agreed that for outdoor temperaturesabove acertain degree of temperature, artificial humidification is notnecessary, and this temperature wil be hereinafter referred to as 44 F.,for convenience of exposition. Accordingly, the thermostat I is set toopen the circuit to the electrically operated moisture control valvewhen the outdoor temperature rises to a degree of temperature such thatthe temperature within the room at the window pane is approximately 44F., and is set to close the circuit when the temperature, at the windowpane, decreases below 44 F. When the temperature, at the window pane,decreases below 44 F., the thermostat 1 operates to close the circuit tothe motor 6 of the oil burner to raise the temperature of the room, theoperation of which is hereinafter described in detail, and as is wellknown, when more heat is supplied to the room air the relative humidityof the room air decreases. Upon a decrease in the relative humidity ofthe room air, the humidostat will operate to permit the electricallyoperated valve to open the valve port to permit moisture to be added tothe room air until such time as the relative humidity, at the windowpane. is raised to 98% relative humidity. Thus, it will be seen that inwinter the thermostatand humidostat in connecti n with a heating plant,coopera e to control the humidity of the air in a heated room so as tomaintain the moisture content of the room air substantially at the dewpoint of outdoor temperature for all outdoor temperatures below apredetermined degree, such as a temperature of 44 F. at the window paneand to maintain the room air at the highest possible relative humidityduring outdoor temperatures below a predetermined degree of temperaturewithout resultant precipitation .of moisture from the room air upon thewindow pane.

The humidostat may .be set to maintain the relative humidity at thewindow pane at substantially 98% relative humidity by arranging thecontact I8 at a distance from contact M of lever I! such that when therelative humidity decreases below 98% the expansible-contractibleelement 8 will have contracted sufliciently to permit engagement of thecontact M with contact l8 and when the relative humidity rises to 98%the expansible-contractible element will have expanded motor 6 of theoil burner.

sufilciently to move contact 14 out of engagement with contact 18. Thismay be accomplished in the present humidostat device by pivoting theplate I] in a direction to move contact 18 toward contact l4 and toaccurately obtain the desired spacing between the contacts, the contactl8 may be adjusted in relation to contact H by means of the screw 2| onthe end of which the contact I8 is fixed. For winter operation, the arm22 of the thermostat 1 is spaced from the contact 25 at a distance suchthat arm contact 23 will make contact with the fixed contact 25 when thetemperature of the room air at the window pane decreases below 44 F.Thus, for all temperatures below 44 F. at the window'pane within theroom, the contacts 23 and 25 will be in engagement and if the contactsl4 and I8 of the humidostat are also in engagement, the solenoid valve40 will be energized by reason of the circuit being closed theretothrough lead wires 35, 31, 42 through the solenoid lead wire 44 andbackto the transformer secondary. When the solenoid is energized, thecore or valve 40 is raised, thus opening the valve port in the moistureconveying pipe to permit additional moisture to be added to the roomair.

If the outdoor temperature should rise to a degree of temperature suchthat the indoor temperature at the window pane rises to or above 44 F.,then the thermostat arm 22 would tend to move away from the contact 25and move its contact 23 out of engagement with contact 25, thus openingthe circuit to the moisture supply means, or should the relativehumidity of the room air at the window pane rise above 98%, theexpansible-contractible element 8 would expand to move the contact arml2 and its contact M out of engagement with the contact l8, and as aresult, open the circuit to the moisture supply means. Thus, thehumidostat and thermostat, operable in response to humidity andtemperature respectively, constitute switches in an electric circuit,either of which may operate, without the other, to cause deenergizationof the electrically operated moisture control device. Consequently, thesolenoid valve will not be energized to admit moisture to the room airunless both the humidostat and the thermostat are in closed circuitposition. If the relative humidity at the window pane is less than 98%and as a result the humidostat is in closed circuit position, thesolenoid would not be energized until the temperature of the room air,at the window pane, decreased to or below 44 F. to affect the thermostatto close and complete the circuit to the solenoid.

7 When the outdoor temperature decreases to a degree of temperature suchthat the temperature of the room air at the window pane decreases below44 F., the contacts 23 and 25 will engage and when this occurs, therelay switch coil 31! is energized through lead wires 32, 44 and throughthe transformer secondary 34 and lead wire 35. Upon energization of therelay coil 33 the switch 33 is closed and if the temperature of theboiler is below the control device 56 has operated to close the circuitand the circuit is completed through lead wire 51, control device 53,lead wires 54 and 55 and the primary lead wire 41 to the It will beunderstood that on the off phase of the burner, that is, when the roomthermostat is not calling for heat and the temperature of the heatconveying medium in the boiler is decreasing, when it decreases below apredetermined point, which may be taken as 110, the heat coz iveyingmedium in the room radiators is at a still lower temperature and ifpermitted to continue to cool, the radiators would 2,814,558 become coldwan-the result that room" air on culation would cease.' It is also wellknown that when room air circulation ceases the air becomes stagnant orstratifles with the colder air settlin'g at the floor or the room.Consequently, be-

fore the colder air rises and affects the room thermostat, which is forall practicable purposes located substantially midway between the floorand'ceiiing 01' a room, the room temperature and the temperature of theheat conveying me-' the outdoor temperature rises to, or above, acertain degree of temperature which maybe taken as approximately 44 F.However, even it the manual switch is left in closed circuit position,the moisture control valve will not be'enersized, forabove'ate'mperature of 44 F., the

contacts 23 and 28 of the thermostat, which are' in series circuitwiththecontrol valve 2, will not.

dium in the boiler have continued to decrease so that when the roonrthermostat 'does demand heat there is a relatively long period of timebefore the boiler heat conveying'medium is heated sufliciently to raisethe temperatureoi the room As a result, the

to the required temperature. heat conveying medium inthe boiler isheated to a temperature in excess of that necessary to raise thetemperature of the room 'to the temperature for which the thermostat isset and consequen-tly the temperature of the room air is continued' tobe raised after the thermostat-has acted to shut oil! the burner.

be in engagement. when the temperature rises to approximately 80? F.outdoor temperaturejr, above, it is also wellknown that artificialdehumidiflcation is desirable in order to maintain a desired-relativehumidity of the air 1118.100111,

. for comfort. In the present system, the thermostat and humidostatare-adapted to control the operation of the dehumidifier motor'3 inaccord ance with outdoor temperature and the relative humidity of theroom air at the window pane In the present'system, it will be seen. thatthe above mentioned objectionable conditions are obviated by reason ofthe control 56 cooperating Any suitable minimum temperature may be se-'lected, the temperature of 110 F. being herein used for convenience ofexposition. Preferably the minimum temperature selected is such that theheat conveying medium in the boiler will be limited to a degree oftemperature just below the boiling point for a steam heating system orin a hot water system to a temperature which will prevent the radiatorin the room from becoming cold and therefore prevent resultantstagnation of the room air.

The control device 56 is thus arranged to act in anticipation ofa demandfor room heat, when the outdoor temperature decreases and when thetemperature of the boiler is belowa predetermined degree of temperature.By maintaining the circulation ofthe room air, it will be understoodthat the heat thereof is more evenly distributed throughout the roomwith the result that the room thermostat would be affected sooner upon adecrease in room air temperature than would be the case if the air hadbecome strati-' fied or stagnant, Also, since the temperature of theboiler has been raised to 110, the time period necessary for the burnerto raise the temperature of the heat conveying medium to the point atwhich the temperature of the room will be raised to the' requiredtemperature will be relatively short and as a result, the temperature ofthe boiler will not be raised to a degree of temperature in excess ofthat necessary for raising the temperature of the room to the desireddegree so that the temperature of the room will not rise substantiallyabove the desired temperatu e for which the room thermostat is set.

For summer operation, the humidifying appae ratus may be dispensed withby opening the circuit by means ofthe switch 42a to the moisture controlvalve. since it is' generally agreed that artificial humidification isnot necessary when respectively, to maintain a desired relativehumidityof-the air in a room. For summer operation, the plate I! is pivoted in adirection so as to move the contact I 9 toward the contact I 5 of thearm 12, to obtain a space therebetween such that theexpansible-contractible element 8 will move the arm contact l5 intoengagement with contact I 9 when the, relative humidity at the windowpane is at, or above, a desired point, for'example relative humidity atthe window pane. The contact 2401 the thermostat arm 22 is arrangedrelative to the contact 26 so that it will engage therewith when theoutdoor temperature rises to a temperature at which artificialdehumidification is desired, which temperature may be assumed to be 80F. Accordingly, if the relative humidity of the room air at the windowpane increases to or above 50% relative humidity, theexpansiblecontractible element 3 will expand and move the contact l5into engagement with the contact l9 and if the outdoor temperature is at80 F. or, so that the contact 24 is in engagement with contact 26, thenthe circuit is closed to the controller of the motor 3 through lead wire35, the secondary of transformer 34, lead wire 44 and lead wires 38 and53. When the circuit is thus closed to the controller of the motor 3,the motor operates the dehumidifying apparatus, which apparatus may beof the type which supplies dehumidified air to t the room or of thetype-which operates on the condensator principle, or any other suitabletype. When the relative humidity of the room air at the window pane isdecreased to 50% or lower, the expansible-contractible element 8contracts, breaking engagement between the contacts 15' and i9 andthusopening the circuit-to the controller of the motor 3, or when thetemperature of the .room air at the window pane decreases below 80'."F.,the thermostat I will operate to open the circuit to the controller ofthe motor 3.

Referring now to Fig.- 2, there is shown an air conditionin'gsystemsimilar to the systemshown in Fig.1, except that a diiferent type ofhumidostat is employed and one which is automatic in that adjustment isnot necessary when changing from winter to summer operation or viceversa. This humidostat, like that of Fig. 1, includes a pivotal contactarm or switch 58, an expansiblecontractible element 59 for operating thearm,

pivotal arms 65 and 66 respectively which are mounted on the board 9 andpreferably arranged in relation to arm 58 so that the free ends of thearms 58, 65 and 8B are adjacent each other with the contacts BI and 62of arm 58 between and in alignment with the contacts 63 and 54 of levers65 and 66 respectively. A spring 61 is provided for urging the pivotallevers 65 and 56 toward each other. The levers 65 and 6B are eachprovided with an adjustable stop 68 and 69 respectively which may bescrews, as shown, threaded into fixed bracket members mounted on theboard 9. The stops or screws 68 and 69 are arranged between the pivotallevers 65 and 66 so that the ends of the screws are in position to bearagainst the adjacent sides of the lever arms 65 and 66 and toward whichthe spring 61 under tension tends to move the lever arms. The lever arm65 cooperates with the lever arm 58 to control the operation of thehumidifying means for winter operation while the lever arm 56 cooperateswith the arm 58 for controlling the dehumidifying means for summeroperation.

Mounted on the board 9 is a bimetallic temperature responsive element Ihaving one end fixed to the board 9, such as by a bracket I2, the otherend II being free and in the form of a switch arm for movement inresponse to changes in temperature at the window pane. The arm isprovided with a pair of contacts I3 and I4 which are fixed thereto onopposite sides of the arm and near the end thereof. Contacts I5 and I6are mounted on the board 9, one on each side of the arm II for engagingwith contacts I3 and I4 respectively. Preferably, the contacts I5 and I6are acfiustable and to this end, the contacts may be mounted on the endsof screws II which are threaded in brackets I8 mounted on the board 9.For winter operation, the contact I5 is positioned relative to contactI3 of the temperature responsive element a distance such that thecontact I3 will engage contact I5 when the temperature at the windowpane is ator decreases below a predetermined degree of temperature,which may be taken as before at 44 F. The contact I6 is spaced from thecontact I4 of arm II such that when the temperature at the window paneincreases to or exceeds a predetermined degree of temperature, which maybe taken at approximately 80 F., arm II will have moved sufiiciently sothat its contact I4 will engage contact I6 and when the temperature atthe window pane decreases below 80 F., contact is broken. The contact I6of the temperature responsive element is connected to the controller ofthe dehumidifier motor 3 by means of a lead wire BI and the con-' tact64 of the humidostat is connected to the dehumidifier 3 by means of alead wire 82. The temperature responsive element I0 is connected by thelead wire 35 to the secondary of the transformer 34 and the arm 58 ofthe humidostat is connected to the transformer secondary by means of alead wire 84. The thermostat I0 and humidostat thus being in seriescircuit so that the dehumidifier motor is not energizable to dehumidifythe air of a room unless the circuit thereto is closed by both thethermostat I0 and the humidostat. Or in other words, the dehumidifiermotor 3 is not energized unless the temperature at the window pane isabove 80 F., and the relative humidity of the room air at the windowpane is above 50%.

The humidostat and thermostat are also in trol valve 2 for controllingthe admittance of moisture to a room in winter. The moisture controlvalve is connected by means of a lead line 88 v to the contact 63. ofthe lever 65 and to the contact I5 of the thermostat element by means oflead wires 81 and 88 in which a manually operatedswitch 89 may beprovided, if desired. It the temperature at the window pane is below 44F., the thermostat will close the circuit through energization of therelay switch coil 33 to the minimum control device 56. If thetemperature in the boiler is below 110 F., then the circuit is closed tothe burner motor 6 and the temperature of the boiler raised to 110 F.,in anticipation of the operation of room thermostat to close the circuitthrough control 53 because of decrease in outdoor temperature. Thetemperature of the boiler is thus prevented from decreasing to anexcessive low degree of temperature and sufiicient heat is supplied tomaintain room air circulation so that the heat of the room is thoroughlydistributed with the result that the room thermostat will be affectedsooner than it would be if the air of the room was permitted tostratify. If the relative humidity of the room air at the window pane isbelow 98%, which is likely after heat is supplied to the room, thecontrol device 2 will be energized, opening the valve port to admitmoisture to the air. It will be seen that if either the temperature atthe window pane increases above 44 F., or the relative humidityincreases about 98%, that the circuit to the moisture control valve willbe broken thus stopping the ficw of moisture to the room air.

The operation of the automatically adjustable humidostat of the airconditioning system of Fig. 2 is as follows: When the outdoortemperature decreases below a predetermined temperature, which may betaken as before at 44" F., artificial humidification of the air of aroom may be necessary to the comfort of .persons therein while fortemperatures above the predetermined outdoor temperature, artificialhumidification is not necessary. Accordingly, the temperatureresponsiveelement I8 is arranged to move its contact I3 into engagementwith its cooperating contact I5, in the circuit of the moisture supplymeans, when the outdoor temperature decreases below the predeterminedtemperature of 44 F. The desired relative humidity of the room air to bemaintained for all outdoor temperatures below 44 F., is, of course,approximately 100% relative humidity at the window pane but slightlyless than 100% or say 98% so that condensation of room air moisture willnot take place on a window pane or other heat transmitting room wallsurface. Accordingly, contacts 63 and BI of the humidostat, which are incircuit with the moisture control means 2, are arranged to part and openthe circuit to the moisturesup-ply means to discontinue the supplying ofmoisture to the room air when the relative humidity thereof increases toapproximately I00% relative humidity. Since v the contacts I3 and I5 ofthe thermostat and series circuit with the magnetically operated conthecontacts GI and. 63 of the humidostat are in series circuit with themoisture supply control means 2, it will be seen that additionalmoisture will not be supplied to the room air unless the contacts of thethermostat and also the humidostat are in closed circuit position. As aresult, the opening of either set of contacts opens the circuit to themoisture supply control means whereupon the supplying of moisture to theroom air will be discontinued.

As previously stated, it the outdoor temperature decreases below atemperature of 4413, the contacts 13 and of the thermostat will be inengagement, and if the contacts .6i and B3 of the humidostat are inengagement, then additional moisture will be supplied to the room air.the relative humidityof the room air at the windowpane decreases belowthe desired relative duced to relative humidity, the circuit to thedehumidifying device will be broken after ensagement of arm with itsstop member 09.

It willbe noted that between outdoor temperatures from 44 F. to F.,conditioning of the room air is not necessary to the comfort of personstherein while below and .above these temperatures the room air ishumidified and dehumidified respectively.

The arm will then be moved away from its stop member 68 as shown in Fig.5.7"

As the relative humidity of the room air is increased, the moistureabsorption element ll exmods and moves the pivoted arm ill in acountor-clockwise direction, as seen on the drawings.

As the .arm' 58 is moved .by the element 68, the arm 65 is drawn towardits contact '88 by the spring 61 and the contacts 83 and Si of thepivoted arms are held in engagement by the spring 81. When the relativehumidity of the room air surrounding the element 59 is substantially butless than relative humidity, the arm 65 will be in engagement with itsstop member 68 after which additional movement of arm 58 will result inthe parting of the contacts 6i and 83 and, Q

therefore, the discontinuing of the supplying of moisture to the roomair.

When the outdoor temperature rises above a predetermined temperaturewhich may be taken as before at 80 F., then artificial dehumidiflcationof the air of a room may be necessary to the comfort of persons therein.Accordingly, the thermostat i0 is arranged'to move its contact; 16 intoengagement with cooperating contact E8, the contacts it and it being incircuit with the dehumidliying device 3. The desired relative humidityof the room air may be determined and which will here be referred to asbefore as 50% relative humidity, for convenience of exposition, althougha lower relative humidity may be desired. The contact 62 and the contact64 of the humidostat are arranged relative to each other and to the stopmember 69 so that the contracts will engage when the relative humidityof the room air at the humidosiat is 50% relative humidity. At thispoint it will be noted that between 100% and 50% relative humiditycontacts BI and 62 will bothbe in engagement with their respectivecontacts 63 and 64. However, it will be seen that both the moisturesupply control means and the dehumidifying means will not be energizedfor only one of the pairsof cooperating contacts of the thermostat willbe in engagement depending upon the temperature of the outdooratmosphere. When the outdoor temper- From the foregoing description, itwill now be seen that .I have provided a new and iinproved method of andapparatus for conditioning the air oi a room or other enclosed space. Byutiliza thermostat and a humidostat arranged to c erate in controllingthe admittance of moist to the air of a room in accordance with decreasein outdoor temperature below a predetermined degree of temperature, anddecrease in relative humidity of the room air at outdoor temperature,respectively, it will be appreciated that the room air will bemaintained at the highest possible relative humidity without danger ofprecipitatlonoi' room air moisture on a window pane. In addition, itwill be appreciated that when the outdoor temperature decreases belowthe predetermined degree of temperature, the thermostat in cooperationwith the ,minimum control device prevents the radiators in 'a roomfrombecoming cold to pregent stagnation or stratification of the room air.The advantages of maintaining gravity circulation of the air in a roomis that the heat in the room is more evenly distributed by the movingair so that at the level of the thermostat in the room the air is morerepresentative of the general condition of the air throughout the roomthan itwould be if the air was permitted to stratify with the colder airat the floor. Furthermore, since the temperature of the heat conveyingmedium in the boiler is brought up to a degree of temperature, forexample necessary to maintain the radiators warm when the outdoortemperature decreases below a certain de- 'gree of temperature, it willbe appreciated that a demand for heat by the room thermostat isanticipated. Consequently, when the room thermostat does demand heat, itwill be understood that a shorter-time period will be required by theburner to raise the temperature of the boiler to ature increases above atemperature of 80 F.,

contacts 14 and 16 of the thermostat will be n engagement and if therelative humidity. of the room air surrounding the' humidostat is above50% relative humidity'then contacts 62 and 64 of the humidostat will bein engagement through movement of the arm 58 due to t he expansion ofthe element 59. As a resultfthe circuit of the dehumidifying device willbe closed whereupon the dehumidifying device will act to reduce therelative humidity of the room air. relative humidity of the room air hasbeen re- When the degree of outdoor temperature.

the required degree of temperature necessary to satisfy the roomthermostat than would be the case if the boiler temperature haddecreased to the point where the room radiators would be cold.Furthermore, by reason of the fact that the boiler temperature can bequickly raised to the required temperature to satisfy the roomthermostat, it will be appreciatedthat the heat conveying medium in theboiler will not be raised to a degree of temperature which would. causeundue increase in room temperature after the thermostat is satistied.Another advantage of the present invention resides in the method of andapparatus for maintaining the relative humidity of the air in a room atthe desired relative humidity for comfort for all outdoor temperaturesabove a predetermined In addition, I have provided apparatus for'mainta-ining the relative humidity of af room at the desired per centfor both winter and. summer and which is automatic in that no adjustmentis necessary when changing from summer to winter or vice versa.Furthermore, I have provided for arranging the thermostatand-humi'dcstat controls in relation with a window pane or'other heattransmitting room wall surface in a new and improved manner whereby thethermostat is affected by changes in outdoor temperature and thehumidostat is aiiected by the moisture content of the room air but atoutdoor temperature.

What I claim and desire to secure by Letters Patent of the United Statesis:

1. The method of controlling the moisture content of the air in a roomor other enclosed space which comprises raising the moisture content ofthe air in the room substantially to the dew point of the Outdooratmosphere for all outdoor temperatures below a predetermined degree oftemperature, and discontinuing the supply of moisture to the air foroutdoor temperatures above said predetermined degree whereby to maintainthe room air at the highest possible relative humidity during outdoortemperatures below said predetermined degree without substantialprecipitation of moisture from the room air upon a window pane or otherheat transmitting room wall surface.

2. The method of controlling the moisture content of the air in a roomor other enclosed space which comprises raising the moisture content of,

the air in the room substantially to the dew point of the outdooratmosphere for all outdoor temperatures below a predetermined degree oftemperature, discontinuing the supply of moisture to the air for outdoortemperatures above said predetermined degree whereby to maintain theroom air at the highest possible relative humidity during outdoortemperatures below said predetermined degree without substantialprecipitation of moisture from the room air upon a window pane or otherheat transmitting room wall surface, and at a second predeterminedoutdoor temperature above said first-named predetermined temperaturedecreasing the relative humidity in the room or space.

3. The method of regulating the temperature and moisture content of theair in a room which comprises supplying a heated heat transfer medium tothe room when room air temperature is below a predetermined degree,establishing apredetermined minimum temperature the heating medium forall outdoor temperatures below a predetermined degree to providecirculation of the room air and simultaneously with the establishing ofsaid minimum predetermined temperature supplying moisture to the roomair for circulation therewith to raisethe moisture content of the roomair substantially equally over and operable upon occurrence of apredetermined low outdoor temperature to render said humidostateifective to supply moisture to the air of the room or other enclosedspace, said responsive means being operable to render said humidostatineffective upon an increase. in outdoor temperatur'e above saidpredetermined low temperature 5. In an air conditioning system forcontrolling the moisture content of the air of a room or other enclosedspace, meansincluding a humidostat operable in response to decrease inthe moisture content of a portion of the room air the room air wherebyto maintain the room air I .at the highest possible relative humidityfor all outdoor temperatures below said predetermined degree withoutresultant precipitation of moisture from the room air upon a window paneor other heat transmitting room wall surface.

6. In an air conditioning system for conditioning the air of a room orother enclosed space, means operable to control admission of moisture tothe air of the room or other enclosed space, a humidostat responsive tothe moisture content of a portion of the air in the room or otherenclosed space and controlling said means, means to cool the portion ofthe room or space air to substantially the prevailing outdoortemperature thereby to maintain the moisture content of the room airsubstantially at the same dew point as the outdoor temperature, andtemperature responsive means operable upon occurrence of a predeterminedhigh outdoor temperature to render said humidostat ineffective tocontrol admittance of moisture to the air of the room or other enclosedspace, said first-named means being operable to admit moisture to theair of the room or other enclosed space only when both said humidostatand said temperature responsive means are calling for moisture.

'7. In a system for conditioning the air of an enclosed space,electrically operated means to control admittance of moisture to the airof the enclosed space, switch means to control said electricallyoperated means, an expansible-contractible element responsive to themoisture content of a portion of the air in the enclosed space andoperable to actuate said switch means, means to cool the air portion toa temperature substantially equal to the prevailing outdoor temperature,and a thermostat responsive to outdoor temperature and in series circuitwith said switch means, said thermostat being operable on predetermineddecrease in outdoor temperature to increase the moisture content of theair in said space only when saidswitch means is in closed circuitposition.

8. In an air conditioning system for conditioning the air of a room orother enclosed space, means operable for controlling the admittance ofmoisture to the room air, a humidostat within the room and at a windowpane thereof operable in response to a decrease in relative humidity atthe window pane below a predetermined percent for controlling theoperation of said means, and a thermal responsive element operable inresponse to an increase in outdoor temperature above a predetermineddegree of temperature to render said humidostat ineffective formaintaining the room air at the highest possible relative humidity andoperable upon a decrease below said predetermined degree to render saidhumidostat efiective for all outdoor temperatures below saidpredetermined degree to maintain the room air at the highest possiblerelative humidity operable to dehumidify the air in the enclosed space,a humidostat responsive to the moisture content of the room air tocontrol said dehumidifying" means, and temperature responsive meansoperable in response to outdoor-temperature to control saiddehumidifying means, said humidostat being inefiective to decrease themoisture content of the air in the enclosed space at outdoortemperatures below a predetermined temperature.

10. In an air conditioning system for controlling the moisture contentof the air in a room or.other enclosed space, means for controlling theadmittance of a dehumidifying medium to the room air, a humidostatdisposed within the room and adjacent a window pane thereof so as to besubjected to substantially outdoor tem perature due to the transfer ofheat through the window pane, said humidostat being operable in responseto an increase in the relative humidity of the air at the window pane tocontrol said means, and thermal responsive means operable in response toincrease in the outdoor temperature for controlling said means toincrease the admittance of the medium.

11. An air conditioning system for a room or other enclosed spacecomprising means for varying a condition ofthe air in said space, asecond means for varying a difierent condition of the air in said space,and controlling means operable upon occurrence of a predeterminedtemperature of the air external of said space for substantiallysimultaneously rendering effective said firstnamed means and saidsecond-named means.

12. An air conditioning system for a' room or other enclosed spacecomprising means for varying a condition of the air in said space, meansfor automatically regulating said condition varying means, a secondmeans for varying a different condition of the air in said space, meansfor automatically regulating said second-named condition varying means,and controlling means operable upon a predetermined temperature of theair external of said space ,for substantially simultaneously renderinginefiective said first-named means and said third-named means. i

13. An air conditioning system for a room or other enclosed spacecomprising means for varying a condition of the air in said space, meansfor automatically regulating said condition-varying means, a secondmeans for varying a condition of the air in said space, means forautomatically regulating said second-named condition varying means,controlling means operable upon occurrence of predetermined temperatureexternal of said space to discontinue operation of-said first-namedmeans and said third-named means, and means for initiating operation ofsaid first-named means irrespective of operation of said controllingmeans.

14. In an air conditioning system for a room or other enclosed space, acasing having inlet and outlet openings for the passageoi; air

, through said casing, said casing having one wall of high heatconductivity exposed to atmosphere external of said space, a thermostatin said casing and operable in accordance with variation in temperatureexternal of said space, a humidity responsive device in said casingoperable in accordance with the humidity of the air in said space at thetemperature of the air in said casing,

sponsive device controlling the circuit of said moisture supplyingmeans, and said thermostat acting to control irrespective of operation'of said humidity responsive device the circuit of said moisturesupplying apparatus and simultaneously acting to control the circuit ofsaid heat supplying apparatus to insure a circulation of air so that themoisture from said moisture supplying apparatus is distributedthroughout the enclosed space.

15. In an air conditioning system for a room or other enclosed space, acasing having inlet and outlet openings for the passage of air throughsaid casing, said casing having one wall of high heat conductivityexposed to atmosphere external of said space, a thermostat in saidcasing and operable in accordance with variation in temperature externalof said space, a humidity responsive device in said casing operable inaccordance with the humidity of the air in said space at the temperatureof the air in said casing, an apparatus for supplying heat to said spaceto maintain a circulation of the air in the enclosed space and having acontrolling circuit, an apparatus for supplying moisture to said spaceand having a controlling circuit, said humidity responsive devicecontrolling the circuit of said moisture supplying means to maintain therelative humidity substantially at but slightly below one hundred percent, said thermostat acting to control irrespective of operation ofsaid humidity responsive devicethe circuit of said moisture supplyingapparatus to discontinue at an apparatus for supplying heat to saidspace to maintain circulation of the air in the enclosed spaceand havinga controlling circuit, an apparatus for supplying moisture to said spaceand having a controlling circuit, said humidity rea given temperaturethe operation of said moisture supplying apparatus and simultaneouslyacting to control the circuit of said heat supplying apparatus so thatair circulation will be established within the enclosed space during thetime moisture is being supplied, an apparatus for dehumidifying the airin said space and having a controlling circuit, saidthermostat actingupon rise of temperature above the temperature at which said moisturesupplying apparatus is discontinued to establish the controlling circuitof said dehumidifying apparatus, and said humidity responsive devicecontrolling the circuit of said dehumidifying apparatus under thedomination of said thermostat.

16. The method of regulating the condition of the air within an enclosedspace comprising the supplying of water vapor to the enclosed space tomaintain a dew point temperature within the space just below thetemperature of a wall sur- ,face having a high rate of heat transfer,rendering said supply effective upon the attainment by the wall of apredetermined minimum temperature, and establishing circulation of theair within the enclosed space so that the supplied water vapor will beevenly distributed to the circulated air and throughout the enclosedspace.

17. In a control system for a space having a window, the combination ofhumidifying means and heating means for the space, the condition of thespace adjacent the window varying in accordance with changes in thecondition outside of the space, and means located adjacent the windowand responsive to the condition 01' the space adjacent the window forcontrolling the humidifying means and the heating means. 18. In acontrol system for a space having a window, the combination of,humidifying means and heating means for the space, means responsive tospace temperatures for controlling said heating means, the condition ofthe space adjacent the window varying in accordance with changes in thecondition outside of the space, and means including means locatedadjacent the window and responsive to the condition of the spaceadjacent the window for controlling the humidifying means andadditionally controlling the heating means. i

19. In a control system for a space having a window, the combination of,humidifying means and heating means for the space, the relative humidityof the space adjacent the window varying in accordance with changes inthe condition outside of the space, and means including means locatedadjacent the window and responsive to the relative humidity of the spaceadjacent the window for controlling the humidlfying means, saidthird-named means also including means for controlling the heatingmeans.

20. In a humidity control system for a space,

the combination of humidifying means for the space, means responsive tothe relative humidity of a portion of the space for controlling thehumidiiying means, the temperature of said portion of the space beingaltered by variations in a condition outside of the space, and meansresponsive to the temperature of said portion of the space for renderingthe humidity responsive means ineffective to control the humidifyingmeans.

21. In a control system for a space, the combination of humidifyingmeans for the space, heating means for the space, means responsive tospace temperature for controlling said heating means, and meansresponsive to the condition of the space which is affected by acondition-outside of the space for controlling said humidifying meansand additionally controlling said heating means independently of saidfirst-' named responsive means;

22. In a control system for an enclosed space, means for changing thetemperature of the space, means for changing the humidity of the space,control means sensit ve to the temperature of the space and operable tocontrol said first-named means, means within the space and sensitive tothe space air at a temperature proportional to the temperature externalor the trol said first means, means independent of said first-namedsensitive means and positioned within a second portion of the spaceseparate from said first rtion, said independent means being sensitiveto the temperature of the space I air in said second portion andoperable to control one of said changing means, the temperature of theair in said second portion being-at a temperature variable with thetemperature external of the space. V

24. In a control system for an enclosed space, a first means forchanging a condition of the space, a second means for changing acondition of the space, means within a first portion of the space andsensitive to the air condition within the space and operable to controlsaid first means, means independent of said first-named sensitive meansand positioned within a second portion of the'space separate from saidfirst portion, said independent means being sensitive to the temperatureof the space air in said second portion and operable to control both ofsaid changing means, the temperature of the air in said second portionbeing at a temperature variable with the temperature external of thespace.

25. In a control system for an enclosed space, means for humidifying thespace, means for heating the space, humidity responsive means within thespace and controlling said humiditying means, temperature sensitivemeans within the space and operable to control said heatin meanstomaintain a predetermined temperature in the space, and means independentofsaid temperature sensitive means and positioned within the space andsensitive to changes in temperature external 01 the space forcontrolling said first-named and second-named means.

PHILIP SHERMAN RUSSEL.

